Brown, who underwent scans late on Sunday evening in Perth, could miss the rest of the season and possibly a large portion of next year if his worst fears come true.

Brown fell awkwardly during a marking contest in the third term in the Eagles’ eight-point loss to Fremantle at Patersons Stadium on Saturday night.

Although there did not appear to be any major impact with anybody else on the ground, he grabbed for his knee immediately and was stretchered off the field.

It is feared Brown has ruptured his anterior cruciate ligament.

He underwent scans about 7pm on Sunday and is still waiting to learn of the results.

“I honestly don’t know, I’m just wishing for the best at this stage,” Brown told The Courier.

“It will be mighty disappointing if it’s really bad.”

Regardless of the extent of the injury, it comes as a cruel blow for the former North Ballarat Rebel and Ballarat Swans footballer, who was arguably in the form of his career for the Eagles, playing every match for the year.

In a further twist, it follows a season-ending knee injury he sustained six years ago, where he damaged his other knee.

The 25-year-old missed the entire 2008 season after rupturing the anterior cruciate ligament in his left knee in a practice match against Collingwood in Albany.

Brown’s twin brother Nathan has already been ruled out for the rest of the season after needing shoulder surgery, having also previously missed an entire season with a knee injury in 2011.

The key Eagles defender has performed solidly this year, slotting into the position veteran defender Darren Glass called home before making a shock decision to retire three weeks ago.

West Coast coach Adam Simpson said he feared the worst immediately, but his spirits had been slightly buoyed since the incident.

“I went in thinking the worst,” Simpson said.

“But there is a little glimmer of hope that it might not be as bad as we thought. But a very small chance.”

patrick.nolan@fairfaxmedia.com.au